I certainly don't know more
It's more something I've heard from others and experienced it myself.
It's true that it's a risk, but that's only for an unhealthy snake (sick, to thin, having parasites, ...). Of course you can't always see that your snake is unhealthy... Another thing is, you need to prepare it well. Nothing in the guts, no sudden drops, ... So I agree, it's always a risk.
Otherwise it's a normal cycle they do every year and it will longer their live. During the hibernation they go in a more 'passive mode'. It's like they don't age that much when in hibernation. They also look 'refreshed' once they are out of hibernation.